A structure and an operation of a conventional lateral electric field type liquid crystal display element, and problems thereof will described with reference to FIGS. 1A to 1C. FIG. 1A is a plan view of an element, and FIGS. 1B and 1C are cross-sectional views of the element illustrated in FIG. 1A. The conventional lateral electric field type liquid crystal display element includes: a TFT substrate 14 on which signal wirings 1, scanning wirings 2, pixel electrodes 6, counter electrodes 7, and the like, which generates an electric field to drive a liquid crystal, are disposed; a color filter substrate 15 on which a black matrix 31, a color filter element 32 and an overcoat layer 33 are disposed, the color filter substrate 15 facing the TFT substrate 14; and a liquid crystal 41 which is provided between the TFT substrate 14 and the color filter substrate 15.
In the conventional lateral electric field type liquid crystal display element, as described in Japanese Patent No. 4858820, in order to shield an electric field leaking from the signal wirings 1, an upper side of the signal wiring 1 is covered with upper electric field shield electrode (hereinafter referred to as an “upper shield COM electrode 5”) having a common potential (hereinafter referred to as a “COM potential”) so as to cover the signal wiring 1 with being superposed thereon through an insulation film such as an inorganic insulation film 23, organic insulation film 24, and a lower electric field shield electrode (hereinafter referred to as a “lower shield COM electrode 104”) extend on a lower side of the signal wiring 1 parallel to an extending direction of the signal wiring 1 adjacent to both sides of the signal wiring. The above-described conventional lower shield COM electrode 104 is formed of a metal wiring by using the same process as the process of forming the scanning wiring 2 in the same layer as the scanning wiring 2 through a gate insulation film 22 with respect to the signal wiring 1.